Utah Professor Wins Award for Work on LED Fabrication

Distinguished Professor Gerald Stringfellow of the University of Utah, a former dean of the University’s College of Engineering and a pioneer in LED technology, was awarded a top research prize for his career-long work in the process for making LEDs.
Stringfellow’s method for fabricating LEDs is used today for producing all the LEDs that go into LED TVs, cellphone screens, LED computer monitors, and a new wave of LED light bulbs and fixtures.Stringfellow, serves as a Distinguished Professor in the University’s departments of materials science and engineering and electrical and computer engineering. He will receive the International Organization for Crystal Growth’s Frank Prize, the top award given for semiconductor growth during a ceremony Aug. 8 in Nagoya, Japan.

Stringfellow, serves as a Distinguished Professor in the University’s departments of materials science and engineering and electrical and computer engineering. He will receive the International Organization for Crystal Growth’s Frank Prize, the top award given for semiconductor growth during a ceremony Aug. 8 in Nagoya, Japan.

“I feel very lucky to have found a niche where the talents I have could be applied to something that has made such an enormous influence on the world,” says Stringfellow, who also was the dean of the University’s College of Engineering from 1998 to 2003.

While Stringfellow worked as a group manager with HP Labs in Palo Alto, California, in the 1970s, he began developing a new process to create LEDs with multiple colors that need much less power.

“My boss said we have to figure out a better way to make LEDs. He said, ‘Jerry, go and spend three months just thinking about this.’ And that’s what I did,” Stringfellow remembers. “My whole attention was focused on this.”

Stringfellow suggested a process called organometallic vapor-phase epitaxy (OMVPE) for growing new semiconductor alloys. The process uses a chemical reaction to grow layers of materials such as Aluminum, gallium, indium and phosphorous on a substrate to create red, orange, yellow and green LED crystals. The process is known by other names including metalorganic chemical vapor deposition (MOCVD) and Metalorganic vapor phase epitaxy (MOVPE). In the OMVPE process, the crystal growth results from a chemical reaction and not from direct deposition as in molecular beam epitaxy (MBE). The growth takes place in a gaseous phase at moderate pressure and not in a vacuum.

HP quickly used the advance to make better HP handheld calculators that employed red LEDs for the display. Stringfellow brought his research to the University of Utah and was hired as a professor in 1980. He made substantial conceptual advances in the field and would later publish a book on his epitaxy process that has now become the bible for the science of growing LED crystals.
“All commercial LEDs are made by this process,” he says.

Stringfellow’s work, along with the later contributions of three Japanese researchers for making blue LEDs led to the creation of LEDs used in flat screen LED-backlit televisions, cellphones, and new LED light bulbs that are much more efficient than incandescent bulbs. LED technology has also been widely deployed in traffic and pedestrian lights in addition to automotive taillights.

Stringfellow earned other top awards for his research, including the John Bardeen Award from The Minerals, Metals and Materials Society and the Rosenblatt Prize from the University.

Gianluca Lazzi, chair of the U’s Department of Electrical and Computer Engineering commented, “Jerry’s contributions to semiconductor crystal growth are nothing short of exceptional and paved the way for pioneering advances in light-emitting diodes, solar cells, and fiber-optic communications.”

“While Prof. Stringfellow’s invention of organometallic vapor-phase epitaxy facilitated the commercialization of light-emitting diodes and improved the TV and computer displays we all use, its greatest benefit to society is in the energy savings that these devices brought about,” said Richard B. Brown, dean of the University of Utah’s College of Engineering.

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